The manner in which children manage their own emotions is crucial to their success in school, at home, and in life. The aim of this longitudinal study is to examine how parental socialization of emotion during the period rapid language development influences the development of effective emotional self-regulation in preschoolers. A community-based sample of 18 month olds and their parents are followed from 1.5 to 4 years of age. It is predicted that the level of a child's language during these years, affects a child's ability to self-regulate emotions at age 4. We predict that the quality of self-regulation predicts child behavior problems with social competence. These developmental processes are studied in families in a lower range of family income because there is likely to be more risk of emotional stress in these families. Economic stress associated with lower income is known to be a risk factor for parents and for their children's social competence and probability of behavior problems. The study includes assessment of how economic stress, marital conflict, and parenting hassles affect the ways in which families interact about emotional events and how this affects the child's ability to develop new and more effective ways to manage emotion when adult support is not available. The participants of the study are 150 families with an 18-month old boy or girl at the first visit. During the three years of the child's life under study, the family is visited at home 4 times and the mother and child visit the lab 4 times. The findings will assist in building a theoretical model for the role of language in the socialization of adaptive emotional functioning and in risk for behavior problems.